Quote
The claimer didn't really state a line of play, he assumed that any line of play by declarer would have to give him two tricks at the end. 70D2 says that a defensive claim can't depend on his partner doing anything specific, but it's silent about depending on declarer's plays. In the footnote about "normal" lines of play including careless or inferior plays, are we supposed to allow carelessness only by the claimer, but expect the opponent(s) to play like experts, even if they freely admit that they would not have? Is that implied by the clause that says that doubtful points should be resolved against the claimer?
It feels wrong to punish a claimer when he actually was going to get those tricks. I suppose this serves the greater good of ensuring good claims: a player should not claim when he can't be sure that he'll always get the tricks. But we don't rule against a claimer when their line of play wouldn't actually work against all possible lies of the cards, but happens to work with the actual lie (e.g. he says he's going to draw trumps in N rounds, which requires that trumps be divided suitably, we allow it if they are, even if he didn't say how he would deal with a bad break). But the difference there is that the opponents can't do anything about the lie of the cards, but they can do something about their choices of play, and the claimer shouldn't be allowed to assume the opponents will play inferiorly.